Musnad Ahmad 30:1187

Rawh narrated to us, Ibn Jurayj narrated to us, al-Nu’man ibn Rashid informed me that Ibn Shihab informed him, from Sa’id ibn al-Musayyib, from Abu Hurayrah, from the Prophet, peace and blessings of Allah be upon him, that he said: "If one of you eats, let him eat with his right hand, and let him drink with his right hand, for indeed the devil eats with his left hand and drinks with his left hand."